Mangaoraka Stream at Corbett Rd.

The lowland monitoring site for Mangaoraka Stream is at Corbett Road in the lower catchment.

Water quality is moderate with most aspects within national guidelines although maximum values, particularly for nutrients and bacteria, may not meet guideline values. This is due to dairy farming being the predominant land use in the catchment above the site. However, despite the very high proportion of agriculture in this catchment, nitrogen concentrations compare well with other Taranaki mid catchment sites. Phosphorus levels in the Mangaoraka Stream are generally lower than streams with headwaters in the National Park, where natural sources of phosphorus are high. The most recent seven-year trends indicate that all measured parameters are stable.

TRC conducts flow-adjusted water quality trend analysis based on NIWA protocols and guidelines (following Scarsbrook and McBride 2007), which is available at https://www.trc.govt.nz/healthy-waterways-report-2016/. Water quality trend data is not displayed on the LAWA website for this site.

The Council also monitors ecological health at this site. We use an ecological index based on the macroinvertebrate communities (tiny animals including insects, crustaceans, molluscs, worms and leeches) found in waterways to measure ecological health.

Macroinvertebrate data for Taranaki shown on LAWA may vary from some data reported elsewhere by the Taranaki Regional Council. This variation is because the level of macroinvertebrate identification used by the TRC has some minor differences from that used by other Councils and LAWA, affecting the taxonomic richness and % EPT taxa scores. Taranaki Regional Council also uses Macroinvertebrate Community Index (MCI) scores which have been modified to reflect the conditions experienced in Taranaki, while the scores shown here are based on the National MCI scores. For more details, the full state of the environment report is available at https://www.trc.govt.nz/council/plans-and-reports/environmental/environmental-monitoring-technical-reports/

Scientific Indicators

Scientific data for this site

Can I trust this data?

This dashboard shows information on the data collected by the regional councils for water quality indicators, analysed as state and trend.

State

State shows how the median of samples from this site compares to other sites.

This site is a Lowland Rural site. Currently showing the state of this site compared to:

The Cawthron Institute has worked alongside regional councils to verify the processes and methods used for data collection, laboratory analysis of samples collected and the statistical analysis and interpretation of the results presented.

If all Cawthron ticks are green, then you can trust this data. However, if one or more ticks are orange, then conclusions should be treated with some caution.

All samples were collected using approved field protocols and have been analysed in accredited laboratories. Therefore the data shown here has been collected and analysed following best practice.

State

All samples were collected using approved field protocols and have been analysed in accredited laboratories.

Trend - SAMPLING FREQUENCY

Samples are collected monthly at this site. Proposed national guidelines suggest monthly sampling is required for trend analysis. Therefore, any trends shown here are based on best practice in terms of sampling frequency.

Bacteria

E. coli

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State

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State

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{{nofMsg(ECOLI.NofMedianScore)}}Annual median

N/A

NOF BandAnnual median

Trend

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Sample history at this site

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E. coli samples for Mangaoraka Stream at Corbett Rd.

n/100ml

What is this graph showing me?

This graph is displaying E. coli concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

What do the icons mean?

It is important to note that changes to the National Policy Statement for Freshwater Management 2014 were announced in August 2017. The changes have removed the below set of criteria for E. coli, and any reference to this use of water (i.e. occasional immersion). The new criteria, effective from 6 September 2017, are for the use of water for swimming and other full contact, sustained exposure activities (diving, surfing etc). The data on LAWA has not yet been updated to reflect the new requirements.

The bands for E. coli are as outlined in the NOF for freshwater:

A

Water quality is considered suitable for the designated use.People are exposed to a very low risk of infection (less than 0.1% risk) from contact with water during activities with occasional immersion (such as wading and boating).

B

Water quality is considered suitable for the designated use.People are exposed to a low risk of infection (less than 1% risk) from contact with water during activities with occasional immersion (such as wading and boating).

C

Water quality is considered suitable for the designated use.People are exposed to a moderate risk of infection (less than 5% risk) from contact with water during activities with occasional immersion (such as wading and boating).

National bottom line: Annual median 1000 n/100mL.

D

Water quality is not considered suitable for the designated use.People are exposed to a high risk of infection (greater than 5% risk) from contact with water during activities with occasional immersion (such as wading and boating).

Clarity

State

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Trend

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Sample history at this site

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Black Disc samples for Mangaoraka Stream at Corbett Rd.

metres

What is this graph showing me?

This graph is displaying Black Disc readings over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

State

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Trend

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Sample history at this site

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Turbidity samples for Mangaoraka Stream at Corbett Rd.

NTU

What is this graph showing me?

This graph is displaying Turbidity levels over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Nitrogen

State

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Trend

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Sample history at this site

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Total Nitrogen samples for Mangaoraka Stream at Corbett Rd.

g/m3

What is this graph showing me?

This graph is displaying Total Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

State

Trend

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Sample history at this site

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Total Oxidised Nitrogen samples for Mangaoraka Stream at Corbett Rd.

g/m3

What is this graph showing me?

This graph is displaying Total Oxidised Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Water quality is not considered suitable for the designated use.Impacts on growth of multiple species, and effects starts approaching acute impact level (i.e. risk of death) for sensitive species at higher concentrations (>20 mg/L).

State

Trend

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Sample history at this site

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Ammoniacal Nitrogen samples for Mangaoraka Stream at Corbett Rd.

g/m3

What is this graph showing me?

This graph is displaying Ammoniacal Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

State

Trend

Sample history at this site

What is this graph showing me?

This graph is displaying Dissolved Reactive Phosphorus concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

State

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Trend

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Sample history at this site

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Total Phosphorus samples for Mangaoraka Stream at Corbett Rd.

g/m3

What is this graph showing me?

This graph is displaying Total Phosphorus concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Taxonomic richness is the number of different taxa present in an ecological community identified to the best possible level.

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Taxa richness history at this site

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Taxa richness for Mangaoraka Stream at Corbett Rd.

Number of taxa

Percent EPT richness

The median of the last 5 years of data

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EPT are macroinvertebrates that are sensitive to water pollution. These are Ephemeroptera (mayfly), Plecoptera (stonefly) and Trichoptera (caddisfly).

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EPT history at this site

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Percent EPT richness for Mangaoraka Stream at Corbett Rd.

EPT %

Can I trust this data?

The Cawthron Institute has worked alongside regional councils to verify the processes and methods used for macroinvertebrate data collection, processing of the data in the laboratory, quality control in the field and laboratory and the statistical analysis and interpretation of the results presented.

Macroinvertebrates are sampled at this site as part of council's stream health monitoring programme, as recommended by proposed national guidelines.

Sampling - Frequency

Macroinvertebrate sampling is done annually or more frequently at this site as recommended by proposed national guidelines. Therefore, data shown here follow current best practice guidelines.

Sampling - Protocols

This site is a hard-bottomed site and appropriate sampling protocols have been applied. Data shown here have been collected using current best-practice.

Sampling - Habitat

Macroinvertebrate sampling is done in riffle habitat at this site. Data shown here are therefore following best practice.

Sampling - Stand-down period

Macroinvertebrate samples are collected within the first two weeks after a flood greater than three times the median flow at this site. Proposed national guidelines suggest a minimum of two weeks 'stand-down' period after a flood greater than three times the median flow. Therefore, data shown here is not following best practice and conclusions based on this data need to be treated with caution.

Processing - Protocol

Samples at this site have been processed following sampling protocol P1 (semi-quantitative - coded abundance). Data shown here is not following best practice, but are still robust.

Quality Control - Field

Field data collected at this site had no quality control applied to it.

Quality Control - Lab

Data processed at this site has had one of the three Laboratory Quality Control Protocols (i.e., QC1, QC2,Q C3) applied. Data shown here is more robust than data with no laboratory QC applied.